Project OptiMutt - Finished

[Hcp22]

his will be fun and educating built to follow as usual Marc

[Coelacanth]

Does the bellcrank differ much from the original part ???

Quite a bit. But should function better, with a servo saver installed on the servo itself. It's ball-raced & has zero play. The only play will be in the servo saver.

[Bormac]

Such an inspiring build Marc. Very cool mate. I watch with much interest on your outcome mate.
Cheers-Jason

[Coelacanth]

Thanks Jason.

I also want to add that I chose to go with a bellcrank like this because all the hopped-up RC buggies have something similar. You see aluminum & nylon versions of the same idea on RC10's and Kyoshos, A & L's bellcrank is pretty much the same idea. I just hate the neon yella color and I wanted aluminum vs. nylon. It's also more low-profile and less clunky than the stock Optima-style steering setup with integrated servo saver. There's only 2 moving parts instead of...4, I believe. Simpler, smoother, zero slop. It's all good.

[longboardnj]

cool project. always thought of doing this when i had a optima mid. id keep the front end as is no kick up. when i first saw this i thought it was a rc10gt with a motor plate.

[RedScampi]

Very interesting and unique build Marc. It will definitely end up being one of a kind! Can I assume I know which wheels will end up on here?

[Coelacanth]

Very interesting and unique build Marc. It will definitely end up being one of a kind! Can I assume I know which wheels will end up on here?

That was the idea but unfortunately, those wheels would only be mounted for shelf duty...those wheels will only work with tapered friction-fit axles like the original Optima series used. The 68mm Lazer CVDs I'm going to be using require hexes & cross-pins, and I don't think there's a way to combine the old tapered axles with the new CVDs unless they're custom-made...or unless someone can suggest tapered CVD axles that will work with Lazer CVD bones?

[Coelacanth]

I have some updates to share, got quite a bit done tonight. It was getting close to the point of mounting the top deck. I had the stock silver mounting posts of course, but I also had these nice blue posts. They're from some Tamiya parts package I bought a long while back that turned out to be too big for whatever I had in mind for CYANide. At a glance, I figured they were too big for this project too, until I had a closer look...hmm, if the hex ends were cut off, they'd be almost the exact same length as the stock Optima Mid posts! They're also slightly thicker and therefore stronger, not that this was a weak point in the Mid design. But the best thing is how cool they'd look, matching the rest of the blue bits!

Well, the devil's in the details, so I cut off the hex ends with a hacksaw, filed the cut ends smooth and to approximately the same length as the stock posts, and they ended up looking fantastic.

The stabilizer/camber plate is a piece I fabricated from 3mm carbon fiber. The blue ball-ends are Tamiya parts. Just as with CYANide, I had to drill a 3mm hole through the GPM control arms to mount the stabilizer "blue balls". Fortunately, the rear suspension moves freely and smoothly and nothing obstructs.

[Coelacanth]

I fabricated my own part for the left side-plate. It's more like the regular Optima Mid piece than the Turbo Optima Mid SE piece, which has a triangular shape. I believe the latter piece has something to do with mounting the stock MSC/ceramic resistor, so with an ESC, I didn't figure the triangular piece would have any function, so I "abbreviated" it.

The pics show a test-fit of the top deck with the blue posts. The rear half of the chassis is pretty much complete. I like the idea of using turnbuckles for the stabilizers instead of the solid plastic stab links, because it makes them adjustable.

[Mr. ED]

Which rear axle carriers are those? They look perfect for use with M or even frog-sized wheels (not suggesting you should do that )

[Coelacanth]

Which rear axle carriers are those? They look perfect for use with M or even frog-sized wheels (not suggesting you should do that )

Well, you're on the right track! They're for the Tamiya M05, made by Yeah Racing. I liked them because they even come with some nice balls & ball-ends--it seems I can never get enough blue balls.

http://www.yeahracing.com/catalog/m05007d2bu-aluminum-rear-hubknuckle-with-roll-centers-adjustment-design-pi-2997.html?picsize=2

[j0pp3]

Wow, a lot has happened since last time I read this thread. The sway bar solution with turnbuckles was new to me. Looks very cool. I vote for not bending the front chassis. At least I would have tried running the front in "stock mode" first. The front arms have a slight angle anyway. You're right about the Rear Plate (L) part. It should be designed like yours when an ESC is used instead of a mechanical speed control.

I'll keep check for updates in this inspiring thread

Cheers

[isobarik]

DeckPosts1.jpg

Where dd you find those posts ?? possible to get an partnumber ???

mvh Isobarik

[Coelacanth]

DeckPosts1.jpg

Where dd you find those posts ?? possible to get an partnumber ???

I'm gonna have to dig deep to get that answer! I can't seem to find them on eBay, obviously not using the right search words...I'll get back to you when I've got a part number for you.

[Coelacanth]

Got a bunch more done this evening to complete the rear end. Fabricated a rear shock tower from carbon fiber first, then I rebuilt the Kyosho Gold shocks. Once the shock tower was installed, I had to do a bunch of mock-ups & test-fits of the shocks. Even mounting the bottom 4.8mm ball studs in the outer-most holes on the control arms, I discovered the right-side shock would slightly rub against the spur gear cover...so that wouldn't do. I drilled new holes further out and tapped a few 3mm threads, then installed the ball studs. Now, the shocks fit fine, nice smooth action, no obstructions.

I only had 25wt and 35wt shock oil so I tried 35wt...I would've gone with 30wt but I seem to have misplaced it...anyway, it might be a tad too heavy, but I'll wait until the car is finished with electrics installed before I make a final decision.

I must say all that blue & champagne gold is looking really sweet! The wheels & tires are not what I plan to install in the end, I just mounted them to adjust camber, suspension & shock mounting positions.